It is often necessary to mix powder and/or liquid medicaments before dispensing the mixture either by syringe or other means. In such cases, it is desirable to effect the preparation of the mixture just prior to the need to dispense the same. Moreover, many medicaments must be prepared, stored, and supplied in a dry or lyophilized form, and must be reconstituted at time of use by addition of a diluent thereto.
A variety of methods have been proposed for adding the diluents to the dry or lyophilized medicament. So-called "open-pour techniques" in which the diluent, which may be a bottle of intravenous solution, is opened and the contents poured into a vial or bottle containing the dry or lyophilized material, have been commonly used. In, such cases, after reconstitution, the liquid is usually returned to the intravenous solution bottle or vial of other source of diluent. Techniques of this nature are unsatisfactory because of exposure to ambient airborne bacterial contamination.
Other proposals to enable reconstitution of medicaments or mixing of such materials have included the "intravenous set transfer" technique which requires an intravenous solution set and stand, and a needle for venting, or a special dispensing cap. Another approach has been to reconstitute using an ordinary syringe to transfer diluent into the container for the dry or lyophilized material. However, here again the needle is exposed to constant airborne contamination.
An improved technique for mixing medicaments of the type described has been disclosed in U.S. Pat. No. 3,882,909 to Robert W. Ogle. By this technique, described as "Trans-A-Jet-1", a fluid transfer device is provided which comprises two parallel fluid passages, both carried by a flange which is generally perpendicular to the passages. A common cover is provided for one end of each fluid passage which forms a fluid-tight seal with the exterior of the passage and abuts the flange. A medicament container having an open end and an imperforate stopper in the open end is provided.
Another device has been proposed in U.S. Pat. No. 3,857,392, issued to Robert W. Ogle, which comprises an intravenous container with a dislodgable septum and dislodging piercer. Mixing by dislodging an intervening septum is also proposed in a device described in U.S. Pat. No. 3,563,415, also issued to Robert W. Ogle.
The present invention is an improvement on the above-described mixing devices and techniques.